One of the objectives in elevator development work is to achieve efficient and economical utilization of building space. In recent years, this development work has produced various elevator solutions without machine room, among other things. Good examples of elevators without machine room are disclosed in specifications EP 0 631 967 (A1) and EP 0 631 968. The elevators described in these specifications are fairly efficient in respect of space utilization as they have made it possible to eliminate the space required by the elevator machine room in the building without a need to enlarge the elevator shaft. In the elevators disclosed in these specifications, the machine is compact at least in one direction, but in other directions it may have much larger dimensions than a conventional elevator machine.
In these basically good elevator solutions, the space required by the hoisting machine limits the freedom of choice in elevator lay-out solutions. Space is needed for the arrangements required for the passage of the hoisting ropes. It is difficult to reduce the space required by the elevator car itself on its track and likewise the space required by the counterweight, at least at a reasonable cost and without impairing elevator performance and operational quality. In a traction sheave elevator without machine room, mounting the hoisting machine in the elevator shaft is often difficult, especially in a solution with machine above, because the hoisting machine is a sizeable body of considerable weight. Especially in the case of larger loads, speeds and/or hoisting heights, the size and weight of the machine are a problem regarding installation, even so much so that the required machine size and weight have in practice limited the sphere of application of the concept of elevator without machine room or at least retarded the introduction of said concept in larger elevators. In modernization of elevators, the space available in the elevator shaft often limits the area of application of the concept of elevator without machine room. In many cases, especially when hydraulic elevators are modernized or replaced, it is not practical to apply the concept of roped elevator without machine room due to insufficient space in the shaft, especially in a case where the hydraulic elevator solution to be modernized/replaced has no counterweight. A disadvantage with elevators provided with a counterweight is the cost of the counterweight and the space it requires in the shaft. Drum elevators, which are nowadays rarely used, have the drawbacks of requiring heavy and complex hoisting machines with a high power consumption.